Ever since Ryota got accepted as a volunteer, he'd run through countless possibilities in his head about what kind of Secret Realm he might enter.
But he'd never—ever—imagined it would turn out to be the world of One Piece.
Wait… hold on. Something didn't quite add up.
[Possible Completion Methods: Become the Pirate King or prevent the birth of a new one.]
[Map Reconstruction: Based on existing exploration data, the Marine Pirate Secret Realm is divided into four seas—East, West, South, and North—connected by a central route known as the Grand Line. The treasure of the previous Pirate King lies somewhere along this route.
Upon entry, all explorers will be randomly teleported to one of the islands. In the first two exploration attempts, all entry points were located in the East Blue. As Gol D. Roger himself began his voyage from an East Blue island, it is speculated that the East Blue is the key region—and also the strongest of the four seas.]
Ryota's expression didn't change, but his thoughts were screaming.
Strongest? Sure, if you're a toddler. The East Blue's the weakest sea.
[An East Blue pirate known as Don Krieg currently dominates the region. In the first exploration, military personnel tested Krieg's strength and estimated it to be mid-blue level. Based on this, pirates of the Grand Line are likely around upper-blue to lower-purple level, no higher than upper-purple. Thus, this Secret Realm is rated Purple Difficulty.
At present, the strongest pirates in this world are referred to as the 'Four Emperors,' the four who come closest to the Pirate King's power. It is recommended that explorers first build strength in the East Blue, defeat Krieg if possible, then enter the Grand Line to investigate and evaluate the Four Emperors for future expeditions.]
Ryota raised an eyebrow. Are you serious right now?
[Regarding the world's power system—technology and individual combat ability coexist. Firearms are powerful, but physical training can reach superhuman levels—fast enough to dodge bullets, strong enough to shatter boulders. Swordsmanship is also a popular discipline.
When explorers enter the Secret Realm, their physical limits will automatically adjust to the world's average standard. Training will steadily increase strength.
Note: a miraculous fruit known as a Devil Fruit exists here. Extremely rare, it grants the eater supernatural power but curses them to lose all strength in seawater.
Only one fruit can be consumed per person. If explorers somehow gather more than ten Devil Fruits and turn them over to their team leader, they may have a chance to challenge the Four Emperors—or even the Pirate King himself. This is unverified—proceed with caution!]
"Caution?" Ryota nearly burst out laughing.
That's your takeaway from all this?!
He skimmed further—lists of Devil Fruit types, notable powers and islands, brief mentions of the World Government. Not totally useless, but… God, it was sloppy.
It looked like none of the previous explorers had even left the East Blue. Everything beyond that was just speculation—pieced together from newspapers. They hadn't even encountered basic concepts like "New World" or "Haki."
Using Don Krieg as a power benchmark? Seriously?
That's where it doesn't make sense.
If the Purple No. 605 Secret Realm really was the One Piece world, and Don Krieg ranked "mid-blue," then this world couldn't possibly be just "purple-difficulty."
People like Doflamingo could wipe out entire nations. The Four Emperors and Marine Admirals were walking natural disasters.
At minimum, this should be Red Infernal. Maybe even Golden Legendary.
Whoever wrote this report needed to be court-martialed.
His initial excitement faded fast. The One Piece world wasn't just "dangerous." It was hellish.
Ryota took a deep breath and went back to reading carefully. The data might be flawed, but it still had some use for the East Blue stage.
Two exploration rounds—two hundred explorers total—randomly dropped across the East Blue. Their footprints covered nearly half its islands, though canonically there were only a handful mentioned in the manga.
Those known islands and events—those were what Ryota focused on memorizing.
Time passed quietly. The military truck carrying the four of them eventually joined a convoy, heading out of Tiger City.
When Mist Star's ever-present fog surrounded them, all four looked up from their folders almost at the same time.
"You've read enough for now, right?" The soldier driving finally spoke. "We'll reach the entrance soon. Any questions?"
They exchanged glances. The rugged older man, Kirishima, spoke first. "Sir, this world's full of pirates, right? If we become pirates ourselves… that might involve robbing or even killing people. When we leave the Secret Realm, will we be punished for that?"
"Damn, old man," Aihara said with a nervous laugh. "That's a creepy question. Killing and arson?" She paled a little, then turned to the soldier. "Sir, these pirates… are they really that violent? What happens if they catch us?"
"Don't call me sir. My name's Arata."
He met her gaze squarely. "And yes. The outcome wouldn't be good. Female explorers especially need to stay cautious.
As for the first question—the answer's… 'within reason.' In the Secret Realm, conflict and casualties are sometimes unavoidable. But don't treat it like a game. If you use it as an excuse to indulge your darker urges or start massacring civilians, you'll be detained after extraction."
Kirishima chuckled. "Got it, sir. Just asking hypothetically."
Arata didn't correct him this time. His eyes flicked to Ryota and Kaito through the rearview mirror.
"What about you two?"
"I'm good!" Kaito said eagerly. The guy was practically vibrating with excitement.
Ryota thought for a moment before asking, "If we defeat that pirate overlord, Don Krieg, will we receive a Secret Pattern when we leave?"
"Yes," Arata replied. "It'll be a white-grade Secret Pattern, which can elevate an ordinary person to first-level Martial Artist—about a thousand kilograms of punching force, a hundred meters in under nine seconds. You'd no longer be considered an average human."
Ryota nodded slightly. That confirmed his theory—the way to earn Secret Patterns was through strength and meaningful achievements that impacted the Secret Realm.
Still, a first-level Martial Artist was nowhere near enough.
Kirishima whistled. "Man, young folks these days sure have guts. Blue-level pirates don't sound like pushovers."
Aihara brushed a strand of hair from her face and smiled faintly. "Ryota-kun's young but… pretty bold."
"Any more questions?" Arata asked. "If not, listen carefully to these final instructions."
All four straightened instinctively.
"First," Arata began, "there are ninety-nine explorers in total for this mission. Three leaders, ninety-six volunteers—nineteen teams, four people each."
The group exchanged looks. Arata nodded. "You're Team One. I hope you'll lead by example in this exploration.
You'll enter the Secret Realm Passage simultaneously. That'll ensure your teleportation zones are close to one another. Once inside, look out for each other—and no killing comrades without cause."
Without cause, huh? Ryota caught the phrasing immediately but wasn't surprised.
Same hometown, same knife in the back.
New world, new betrayals. Pretty standard.
"Second," Arata continued, "remember this address: 407 Loguetown, East Blue. The three team leaders will claim that property as soon as possible.
One month into Secret Realm time, if you've secured a base, send letters to that address. That's how we'll build our intelligence network. If you can, include your own Den Den Mushi number.
Useful intel will be converted into real-world compensation for you and your families. I'm sure you were briefed on that before signing up."
He paused—then his tone hardened.
"But remember this above all."
He turned halfway, eyes sharp. "Never—never—mention anything about our world. Not in letters, not in conversation.
If you do, the Secret Realm will strike you down on the spot. No exceptions."
Ryota felt a chill run through him. That's some Main God Space-level threat.
"Strike us down? Like, what kind of disaster?" Aihara asked nervously.
"Who knows?" Arata shrugged. "Lightning, monsters, divine punishment—it doesn't matter. Just remember the rule.
The Secret Realm has a will of its own. It rewards us with Secret Patterns after completion, doesn't it? So of course, it enforces its own laws too.
The good news is it helps us too. You won't have to worry about language barriers. Once inside, you'll automatically understand and speak the local tongue."
He stepped on the brake and turned fully around.
"Lastly—and most importantly—stay alive. Nothing matters more than that."
The vehicle came to a stop.
"We're here."
He climbed out, opened the back doors, and motioned for them to follow.
Behind them, the other military trucks lined up neatly but remained sealed tight. Even the next truck's windshield was covered with a reflective film—no way to see who was inside.
So each team entered separately, never seeing the others. Hyper-cautious.
Considering my dad's a Demon Clan infiltrator… can't blame them for being paranoid.
Ryota couldn't help but feel like he understood now.
Then he looked up—and froze.
A golden light split the clouds.
The mist tore apart like thin silk, revealing a massive swirling vortex in the sky. It was impossible to see where it ended—its edges burned with symbols that glowed like molten fire, flowing and alive.
"That," Arata said proudly, "is the Secret Realm Passage."
He raised his voice. "Team One—move out!"
Kaito grinned ear to ear and charged ahead.
Aihara followed slowly, her face pale, while Kirishima walked beside her with that unreadable smile still on his lips. Ryota took the right flank, eyes sharp and focused.
One by one, they stepped into the blinding vortex.
When they vanished, the driver's door of the next truck opened, and a tall, thin soldier strolled over with a grin. "So, Arata—how was Team One?"
"Address me as 'Leader,' Deputy Leader Naoya."
"Fine, fine, Leader," Naoya chuckled. "Well? How are they?"
Arata watched the light fade where the four had disappeared. "Just like their background reports said. Not a single simple one among them."
He smiled faintly. "Let's hope luck's on their side."